This is only a trial, where i kept my intermediate and H/L neps, and seeds. Run by a blower at every 45 mins for 15 mins with aid of timer, 2 blocks of ice, floor were laid with wet sphagnum moss. The cover was slightly open to let air in/out, reinforce with wire mesh. The transparent plastic sheet allow for filtered light.
The poly box was left in the open. No ice was added during the day till 7.00pm, though sometimes i missed placing it for 1-2 days.